© Verlag Alexander Just: Dorfbeuern - Salzburg - Brüssel; download unter www.biologiezentrum.at Sauteria 9, 1998 IAL 3 - Proceedings 43-50 CHANGES IN SYSTEMATICS OF CETRARIOID LICHENS Die Veränderungen in der Systematik der cetrarioiden Flechten by Tiina RANDLANE & Andres SAAG Key words: Parmeliaceae, cetrarioid lichens, systematics. Schlagwörter: Parmeliaceae, cetrarioide Flechten, Systematik. Summary: Changes in the systematics of cetrarioid lichens (about 130 species) during last four years are commented. 22 genera are short• ly characterized. Lately described species are listed. Zusarrunenfassuiig: Änderungen in der Systematik der cetrarioiden Flechten (etwa 130 Arten) während der letzten vier Jahre werden kommentiert. 22 Arten werden kurz charakterisiert. Kürzlich beschriebene Arten werden aufgezählt. Introduction The family Parmeliaceae, which consists of c. 60 genera and about 1000 species, has colloquially been divided into three simple but somewhat ill- defined morphological categories: alectorioid, parmelioid and cetrarioid. Alec- torioid lichens are beard-like or truly fruticose, pendant or caespitose. Parme• lioid lichens are clearly foliose, possessing laminal apothecia and pycnidia, and are usually more or less closely adnate to the substrate. Cetrarioid lichens, on the other hand, form a somewhat vague and undelimited group between these two, having a strap-shaped, subfruticose or ascending foliose thallus, posses• sing mainly marginal apothecia and pycnidia. However, this arrangement is based mainly on morphology and, as most morphological characters, often displays a large degree of variability. Evidently, these familiar categories (alectorioid, cetrarioid and parmelioid) have little to do with phylogeny. It was 43 © Verlag Alexander Just: Dorfbeuern - Salzburg - Brüssel; download unter www.biologiezentrum.at convincingly shown already at the beginning of nineties (KÄRNEFELT et al. 1992) that the cetrarioid group of lichens is doubtlessly polyphyletic and therefore all these species cannot be placed in one or two genera as it was done, for instance, by the Russian lichenologist Ksenya RASSADINA (1950) or by the Finn Veli RÄSÄNEN (1952). Ksenya RASSADINA incorporated 76 species into the genus Cetraria. Today we can count more than 130 cetrarioid lichen species which are divided between 22 genera. The process of splitting the polymorphic genus Cetraria was initiated by Dr-s William and Chicita CULBERSONS who presented three new genera - Asahinea, Cetrelia and Platismatia - in 1960-ies (CULBERSON & CULBERSON 1965,1968). These genera are now accepted by everybody without a doubt. We are quite sure that the same will happen to the most of the new cetrarioid genera which predominantly are described on the complex of different characters with special emphasis on the anatomical characters. Four years ago 14 genera of cetrarioid lichens could be listed (RANDLANE & SAAG 1993), at present there are 22 of them. A short review of all cetrarioid genera is presented as following. Ahtiana GOWARD (1985) - 3 species Originally it was described as a monotypic genus for quite a parmelioid- looking lichen A. sphaerosporella, today two other species (A. aurescens and A. pallidula) from North America with yellowish foliose thallus and globose ascospores have been added. Allocetraria KUROK. & M. J. LAI (1991) - 10 species This genus, segregated from Cetraria on thallus morphology and anatomy mainly, originally included three yellowish species from high altitudes in South-East Asia. The most widely known of them is probably the former Cetraria everniella - with the correct name Allocetraria stracheyi now. Our studies have shown that very clear anatomical and pycnidial characters, especially the presence of palisade plectenchymatous cortex and filiform pycnoconidia sepa• rate this genus from other cetrarioid taxa. A number of species have been combined here, including also sorediate and more widely distributed A. oakesiana. Two species - A. flavonigrescens A. THELL & RANDLANE and A. sinensis X. Q. GAO have been described lately. Arctocetraria KÄRNEFELT & A. THELL (1993) - 2 species This new genus has strong morphological affinities to Cetraria but it differs from the latter in certain anatomical (one-layered cortex, paraphyses with extremely broad bases, bifusiform pycnoconidia) and chemical characters (presence of rangiformic acid in medulla). Arctocetraria andrejeuii and A. nigricascens have been converted here. 44 © Verlag Alexander Just: Dorfbeuern - Salzburg - Brüssel; download unter www.biologiezentrum.at Asahinea W. L. CULB. & C. F. CULB. (1965) - 2 species A well-known by now genus which includes species with large foliose thalli missing rhizines; apothecia (rarely present, imperforate) are marginal till entirely laminal. It is worth mentioning that only two and not three species are recognized at present - the third species, a Japanese endemic A. kurodakensis was shown to be conspecific with A. scholanderi (GAO 1991). Thus A. chrysantha and A. scholanderi are the two representatives. Cetraria ACH. (1803) - 33 species, of which 16 are "true". Cetraria comprised 8 taxa when ACHARIUS described the genus. Today it is proposed to delimit the genus as the so-called Cetraria islandica group only and this comprises 16 species (including also 4 species that have been transferred from the former genus Coelocaulon) (KÄRNEFELT et al. 1993). Anatomy of the thallus (usually two-layered cortex) and also of asci (comparatively small axial body and a distinctive amyloid ring structure) are important characters in these re-arrangements. Still, there are 10 more species described originally as Cetrarias that evidently do not belong to this group (C. albopunctata, C. annae, C. antarctica, C. dermatoidea, C. hypotrachyna, C. kurokawae, C. microphylla, C. nova-zelandiae, C. subscutata and C. xizangensis). The material available concerning these species has been sterile or too poor for deciding their true generic location and therefore they are still artificially situated in Cetraria. The suitable generic position is not clear either for the Cetraria fendleri group (four species from North-America), Cetraria melaloma-leucostoma complex (two species from Himalaya) and for Cetraria sepincola but it seems necessary to exclude them all from Cetraria s. str. in the future. Cetrariella KÄRNEFELT & A. THELL (1993) - 2 species Two species, C. delisei and C. fastigiata, differ essentially from Cetraria by their ascus shape (broadly clavate), type of pycnoconidia (sublageniform) and medullary chemistry (gyrophoric and hiascic acids). Cetrelia W. L. CULB. & C. F. CULB. (1968) -17 species This is a well-known and firmly recognized genus where only the number of species may cause some argument. At present we incline to accept the so-called chemical species concept in this genus (CULBERSON, C. F. & CULBERSON, W. L. 1976; RANDLANE&SAAG1991). All the species are characterized by large folious thalli with punctiform pseudocyphellae on the upper surface, apothecia if present are situated laminally and are commonly perforate. 45 © Verlag Alexander Just: Dorfbeuern - Salzburg - Brüssel; download unter www.biologiezentrum.at Cetreliopsis M. J. LAI (1981) - 5 species Another genus with large foliose thallus that was described as monotypic (for Cetreliopsis rhytidocarpa) but now it has turned out to comprise some more species. There are some very well defined diagnostic characters that help to separate the genus from Nephromopsis or even Cetrelia, such as the presence of laminal pseudocyphellae on both surfaces of the thallus, or production of fumarprotocetranc acid in medulla. Cetreliopsis papuae RANDLANE & SAAG, an endemic of New Guinea, is a lately described representative of the genus. Coelopogon BRUSSE & KÄRNEFELT (1991) - 2 species Consists of two species from the southern hemisphere, earlier accommo• dated in Coelocaulon (the latter unit is now included in Cetraria, see above). Both species, C. abraxas and C. epiphorellus are known as sterile only, therefore the anatomy of thallus cortex (one-layered) and also the medullary chemistry (epiphorellic acid) are of great importance. Cornicularia HOFFM. (1794) - 1 species Cornicularia normoerica has quite a unique morphology characterized by a low erect fruticose thallus arising from a rudimentary foliose-squamulose base. Absence of any medullary substances supports its separation from Cetraria. Dactylina NYL. (1860) - 2 species The genus comprises only two species today - D. arctica and D. ramulosa. They both are characterized by hollow fruticose thallus, globose to subglobose ascospores and oblong citriform pycnoconidia. Two earlier Dactylinas - D. madreporiformis and D. endochyrsea - have lately been transferred to Allocetraria (KÄRNEFELT & THELL 1996). The latter genus differs from Dactylina by its compact foliose or fruticose thallus, very broad axial body and filiform pycnoconidia. Esslingeriaiia HALE & M. J. LAI (1981) - 1 species A monotypic genus from North America with the type species E. idahoensis. Gray foliose thallus, marginal up to laminal apothecia and presence of an antraquinone endocrocin in the medulla are diagnostic features for this taxon. Flavocetmria KÄRNEFELT & A. THELL (1994) - 2 species This newly desribed unit includes two yellow coloured erect species, F. cucullata and F. nivalis. A thin one-layered cortex, bifusiform pycnoconidia and presence of usnic acid are the diagnostic characters for segregating the taxon from Cetraria. 46 © Verlag Alexander Just: Dorfbeuern - Salzburg - Brüssel;